The present invention relates to automotive seat recliners and, more particularly, to a manual clutch release seat recliner having a gearing mechanism to permit the controlled reclining of an automotive seat back.
Automotive seats usually comprise a seat bottom that is affixed to a seat frame. The seat frame is mounted to the floor of the vehicle and is usually of a rail type design to allow the forward and rearward adjustment of the seat bottom. The seat back is attached to the seat bottom by a seat back support. If the seat is a reclining type seat where the seat back is rotationally movable with respect to the seat bottom, a locking and release mechanism must be provided. The seat reclining mechanism usually comprises a base that is affixed to the structure of the seat bottom. The seat back support is pivotally mounted to such base as it is desirable to have the seat back move forward and rearward with the seat bottom. The locking and release mechanism by which the seat back is held in a fixed angular relative to the seat bottom has several known forms. One form is a ratchet mechanism wherein a notched wheel is affixed to either the seat back or seat bottom and a pawl is attached to the other. Upon the pawl disengaging the notched wheel, the seat back is released and is free to rotate at its pivot with respect to the seat bottom. Other types of engaging or intermeshing gear type mechanisms all provide a locking and a releasing operation between the seat bottom and seat back.
Certain drawbacks are present in these known seat back locking and release mechanisms. Due to the potentially great forces to which a vehicle seat back can be subjected, a locking mechanism at the pivot between the seat back and the seat bottom must be a relatively sturdy and heavy unit. This is undesirable in the ongoing attempt at decreasing the weight of vehicles to achieve greater fuel efficiency. Another problem with such known locking and release mechanisms concerns the abrupt release and locking of the mechanism. If a passenger desires to rotate the seat back with respect to the seat bottom, and the locking mechanism is a ratchet and pawl assembly, once the pawl is released there is no restraint on the seat back. There is no clutching possible in such an arrangement wherein the seat restraining force could gradually be released to allow the passenger to move the seat as desired and then reengage the locking mechanism. Such known mechanisms are either locked or released with no partial "in-between" settings possible. Such a clutching or partial release operation of a locking mechanism is desirable.
A final problem with such known seat back support locking mechanisms is that a finite number of reclined positions are possible depending on the number of notches in the ratchet wheel. Because of the strength required of the locking mechanism, it is not desirable to make the notches very small and closely spaced to provide many possible reclining positions. Rather, the number of reclining positions is rather limited because of the need to have quite strong notches and protrusions from the ratchet wheel. A locking mechanism having an infinite number of settings is desirable.
Accordingly, it is an object of the present invention to provide an improved reclining seat back locking mechanism.